Twenty birds died at the scene or during transport, while another 12 were euthanized due to their poor condition, according to the Animal Rescue League of Boston.

Rescuers were able to help save 35 of the birds, which were found in the city's Dorchester neighborhood.

In addition to the birds, officials are trying to determine whether three sick cats also reported in the neighborhood were related to the incident. Two of the cats have died, the Associated Press reported.

Multiple state and city agencies were working to determine the cause.

Jason Wells is deputy news director for BuzzFeed News and is based in Los Angeles.